Messages in this thread | | | Date | Fri, 16 Aug 2013 16:31:15 -0400 | From | KOSAKI Motohiro <> | Subject | Re: [PATCH] mm/hotplug: Remove stop_machine() from try_offline_node() |
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>>> This patch removes the use of stop_machine() in try_offline_node() and >>> adds comments to try_offline_node() and remove_memory() that >>> lock_device_hotplug() is required. >> >> This patch need more verbose explanation. check_cpu_on_node() traverse cpus >> and cpu hotplug seems to use cpu_hotplug_driver_lock() instead of lock_device_hotplug(). > > As described: > > | lock_device_hotplug() serializes hotplug & online/offline operations. > | The lock is held in common sysfs online/offline interfaces and ACPI > | hotplug code paths. > > And here are their code paths. > > - CPU & Mem online/offline via sysfs online > store_online()->lock_device_hotplug() > > - Mem online via sysfs state: > store_mem_state()->lock_device_hotplug() > > - ACPI CPU & Mem hot-add: > acpi_scan_bus_device_check()->lock_device_hotplug() > > - ACPI CPU & Mem hot-delete: > acpi_scan_hot_remove()->lock_device_hotplug()
O.K.
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